Surface-modified apricot pits as biochar feedstock and phosphate sorbent

2020 ◽  
Author(s):  
Gerhard Soja ◽  
Stefan Wyhlidal ◽  
Wolfgang Friesl-Hanl ◽  
Kathrin Zwölfer ◽  
Julia Edlinger ◽  
...  
Keyword(s):  
Surface Modification ◽  
Sorption Capacity ◽  
Vegetable Oils ◽  
Liquid Media ◽  
Phosphate Sorption ◽  
Sorption Dynamics ◽  
Negative Effect ◽  
Screw Reactor ◽  
Surface Modified

<p>Pits from fruit like apricots, peaches and cherries are an under-utilized resource. If there is any use at all, they may be extracted for special vegetable oils. Mostly the pits are combusted or left to rot. However, they are also an appropriate feedstock for pyrolytic carbonization. This study investigated the biochar produced from apricot pits for its potential to sorb phosphate from liquid media and from artificial wastewater.</p><p>Shredded apricot pits were pyrolyzed at 450 °C in a lab-scale screw reactor (Pyreka 3.0). Additionally, the impregnation of the feedstock with Mg(OH)<sub>2</sub> before pyrolysis was studied to test the hypothesis that phosphate sorption to biochar takes advantage of metal bridges on the biochar surface.</p><p>The results of isotherm sorption experiments showed that the pre-pyrolysis Mg-surface modification of the pits improved the sorption capacity of the biochar up to 42 mg PO<sub>4</sub>-P/g whereas the unmodified biochar adsorbed only about one tenth. When KH<sub>2</sub>PO<sub>4</sub> was used as the only sorbate, EDX-mapping showed the formation of K-struvite-crystals in the pores of the biochar. Desorption experiments showed a major release of the adsorbed phosphate within a few hours. Sorption competition experiments with phosphate and nitrate showed no negative effect of nitrate on phosphate sorption. Feedstock impregnation with Ca(OH)<sub>2</sub> resulted in more variable sorption dynamics.</p><p>The results could be confirmed by deploying the surface-modified apricot pit biochar for the reduction of the phosphate load in artificial wastewater.</p>

scholarly journals Facile Preparation of Efficient WO3Photocatalysts Based on Surface Modification

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Min Liu ◽  
Hongmei Li ◽  
Yangsu Zeng
Keyword(s):  
Photocatalytic Activity ◽  
Surface Modification ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Impregnation Method ◽  
Light Spectra ◽  
Simple Strategy ◽  
Visible Light Active ◽  
Efficient Charge ◽  
Surface Modified

Tungsten trioxide (WO3) was surface modified with Cu(II) nanoclusters and titanium dioxide (TiO2) nanopowders by using a simple impregnation method followed by a physical combining method. The obtained nanocomposites were studied by scanning electron microscope, X-ray photoelectron spectroscopy spectra, UV-visible light spectra, and photoluminescence, respectively. Although the photocatalytic activity of WO3was negligible under visible light irradiation, the visible light photocatalytic activity of WO3was drastically enhanced by surface modification of Cu(II) nanoclusters and TiO2nanopowders. The enhanced photocatalytic activity is due to the efficient charge separation by TiO2and Cu(II) nanoclusters functioning as cocatalysts on the surface. Thus, this simple strategy provides a facile route to prepare efficient visible-light-active photocatalysts for practical application.

scholarly journals Enhancement of the Congo Red Adsorption Capacity of Biochars by Surface Modification with MgCl2 Pretreatment

2020 ◽  
Vol 42 (10) ◽  
pp. 472-481
Author(s):  
Hee So Oh ◽  
Jae-Soo Chang
Keyword(s):  
Surface Modification ◽  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Congo Red ◽  
Raw Materials ◽  
Physicochemical Characteristics ◽  
Pine Sawdust ◽  
Adsorption Capacities ◽  
Initial Ph ◽  
Surface Modified

Objectives : The physicochemical characteristics of Mg-biochar composites derived from kelp and pine after pretreatment with MgCl2 were analyzed, and their adsorption capacities for an anionic dye, Congo red (CR), were evaluated.Methods : After pretreating 60 g of kelp and pine sawdust in 1 L of 0.1 M MgCl2･6H2O, the raw materials were pyrolyzed at 500℃ to produce Mg-biochar composites (kelp based KB-Mg and pine based PB-Mg). The fundamental physicochemical characteristics of the Mg-biochar composites were examined, and their adsorption capacities for CR were investigated using different initial pH values, adsorption kinetic models, and adsorption isotherm models.Results and discussion : The Mg-biochar composites showed the development of uniform deposits of Mg minerals primarily as MgO crystal on the surface by the surface modification with MgCl2. When the pristine biochars were surface-modified with MgCl2, their adsorption capacities for CR were significantly increased over the entire pH range tested. The CR adsorption process by all biochars was best described with the pseudo-first order kinetics model, and the adsorption isotherm characteristics were better described with the Langmuir isotherm model for all biochars. The Langmuir maximum adsorption capacities for KB-Mg and PB-Mg were 423.0 mg/g and 394.7 mg/g, respectively. It is suggested that the main mechanism for CR adsorption on the Mg-biochars is electrostatic attraction between CR and the biochars.Conclusions : The results showed that surface modification with MgCl2 could greatly enhance the CR adsorption capacity of biochars, and the results demonstrated the great potential of KB-Mg and PB-Mg for CR removal.

Surface modification of ferrite nanoparticles with dicarboxylic acids for the synthesis of 5-hydroxymethylfurfural: a novel and green protocol

RSC Advances ◽  
2016 ◽  
Vol 6 (80) ◽  
pp. 76795-76801 ◽  
Author(s):  
Melad Shaikh ◽  
Mahendra Sahu ◽  
Kiran Kumar Atyam ◽  
Kalluri V. S. Ranganath
Keyword(s):  
Surface Modification ◽  
Dicarboxylic Acids ◽  
Ferrite Nanoparticles ◽  
Solvent Free ◽  
Green Protocol ◽  
Flexible Ligand ◽  
Solvent Free Conditions ◽  
Surface Modified

5-Hydroxymethylfurfural (5-HMF) has been synthesized under solvent free conditions using surface modified ferrite nanoparticles. The flexible ligand modified ferrites showed higher activity than rigid modified ferrites.

Insights on the impact of photophysical processes and defect states evolution on the emission properties of surface-modified ZnO nanoplates for application in photocatalysis and hybrid LEDs

2021 ◽  
Author(s):  
Dhritiman Banerjee ◽  
Payal Banerjee ◽  
Asit Kumar Kar
Keyword(s):  
Zinc Oxide ◽  
Optical Properties ◽  
Surface Modification ◽  
Defect State ◽  
Defect States ◽  
Emission Properties ◽  
Photophysical Processes ◽  
State Densities ◽  
Surface Modified ◽  
The Impact

The effects of surface modification on the defect state densities, optical properties, photocatalytic and quantum efficiencies of zinc oxide (ZnO) nanoplates have been studied in this work. Here, the aim...

Articulating Biomaterials

2015 ◽  
pp. 218-267 ◽  
Author(s):  
Vamsi Krishna Balla ◽  
Mitun Das ◽  
Someswar Datta ◽  
Biswanath Kundu
Keyword(s):  
Surface Modification ◽  
Clinical Performance ◽  
Decisive Role ◽  
Surface Characteristics ◽  
Surface Modification Techniques ◽  
Biological Environment ◽  
Surface Modified ◽  
In Vivo Effects

This chapter examines the importance of surface characteristics such as microstructure, composition, crystallographic texture, and surface free energy in achieving desired biocompatibility and tribological properties thereby improving in vivo life of artificial articulating implants. Current implants often fail prematurely due to inadequate mechanical, tribological, biocompatibility, and osseointegration properties, apart from issues related to design and surgical procedures. For long-term in vivo stability, artificial implants intended for articulating joint replacement must exhibit long-term stable articulation surface without stimulating undesirable in vivo effects. Since the implant's surface plays a vital and decisive role in their response to biological environment, and vice versa, surface modification of implants assumes a significant importance. Therefore, overview on important surface modification techniques, their capabilities, properties of modified surfaces/implants are presented in the chapter. The clinical performance of surface modified implants and new surfaces for potential next-generation articulating implant applications are discussed at the end.

scholarly journals Influence of the surface modification by sanding of carbon textile reinforcements on the bond and load-bearing behavior of textile reinforced concrete

2019 ◽  
Vol 289 ◽  
pp. 04006
Author(s):  
Cynthia Morales Cruz ◽  
Michael Raupach
Keyword(s):  
Surface Modification ◽  
Reinforced Concrete ◽  
Tensile Tests ◽  
Measuring System ◽  
Uniaxial Tensile ◽  
Testing Time ◽  
Textile Reinforced Concrete ◽  
Load Bearing ◽  
Surface Modified ◽  
Bearing Behavior

In the context of the application of carbon Textile Reinforced Concrete (TRC) layers for the durable repair of building surfaces, uniaxial tensile tests on rectangular TRC samples were carried out to compare the bond and load-bearing behavior of an epoxy-impregnated carbon textile and its surface modified version. The aim of the surface modification, consisting of a subsequent coating with epoxy resin and sanding with quartz sand, is the improvement of the composite material regarding crack width reduction and an increase of the load-bearing capacity. A total of 15 series were examined and the parameters: reinforcement type, orientation and ratio were varied. In addition, long-term load tests were conducted. An optical 3D-video measuring system in combination with a DIC-software was used, which allowed the analysis of the process of crack formation during the entire testing time. With the surface modified reinforcement the formation of approx. 1.5 times the number of cracks with averagely 33 % smaller crack widths and up to 50 % smaller crack spacings were observed, regardless of the ratio of reinforcement. The residual behaviour of the series subjected to a permanent load of 1500 MPa over 1000 h showed no reduction of the tensile stress compared to short-term tests.

scholarly journals Electrophoretic Deposition of Carbon Nanotubes over TiO2Nanotubes: Evaluation of Surface Properties and Biocompatibility

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Jung Eun Park ◽  
Il Song Park ◽  
Tae Sung Bae ◽  
Min Ho Lee
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Corrosion Resistance ◽  
Surface Modification ◽  
Electrophoretic Deposition ◽  
Biomedical Applications ◽  
Controlled Drug Delivery ◽  
Chemical Durability ◽  
Surface Modified ◽  
Excellent Chemical

Titanium (Ti) is often used as an orthopedic and dental implant material due to its better mechanical properties, corrosion resistance, and excellent biocompatibility. Formation of TiO2nanotubes (TiO2NTs) on titanium is an interesting surface modification to achieve controlled drug delivery and to promote cell growth. Carbon nanotubes (CNTs) possess excellent chemical durability and mechanical strength. The use of CNTs in biomedical applications such as scaffolds has received considerable attention in recent years. The present study aims to modify the surface of titanium by anodizing to form TiO2NTs and subsequently deposit CNTs over it by electrophoretic deposition (EPD). Characteristic, biocompatibility, and apatite forming ability of the surface modified samples were evaluated. The results of the study reveal that CNTs coating on TiO2nanotubes help improve the biological activity and this type of surface modification is highly suitable for biomedical applications.

Experimental Design of Surface Modification of Expanded Obsidian and Determination of Water Sorption Capacity

2014 ◽  
Vol 1020 ◽  
pp. 823-826
Author(s):  
G.Sh. Hovsepyan ◽  
M.A. Kalantaryan ◽  
T.V. Yedoyan
Keyword(s):  
Experimental Data ◽  
Surface Modification ◽  
Sorption Capacity ◽  
Water Sorption ◽  
Structural Changes ◽  
Ir Spectrometry ◽  
Water Capacity ◽  
Series Of Experiments ◽  
Water Sorption Capacity

The aim of this paper is to study the possibility of expanded obsidian and its modified product use for oil sorption, in that tetraethoxisilane (TEOS) has been used as a modifier. The optimal concentration of the modifier was determined by 50 per cent weight of expanded obsidian. The expanded obsidian was previously activated with 0,1 M solution of hydrochloric acid. IR spectrometry was used to characterise structural changes in the modified expanded obsidian samples. To determine water sorption capacity a series of experiments has been carried out. The analysis of obtained experimental data showed that after surface modification of expanded obsidian water capacity is reduced 3 times after the surface modification of EO.

scholarly journals Facile surface modification of nickel ferrite nanoparticles for inherent multiple fluorescence and catalytic activities

RSC Advances ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 38-43 ◽  
Author(s):  
Souvanik Talukdar ◽  
Rupali Rakshit ◽  
André Krämer ◽  
Frank A. Müller ◽  
Kalyan Mandal
Keyword(s):  
Wastewater Treatment ◽  
Surface Modification ◽  
Nickel Ferrite ◽  
Cell Imaging ◽  
Ferrite Nanoparticles ◽  
Catalytic Activities ◽  
Nickel Ferrite Nanoparticles ◽  
Surface Modified

We have developed bio-compatible magneto-fluorescent NiFe2O4 nanoparticles (NPs) by modifying the surface of the NPs with Na-tartrate. The surface modified NiFe2O4 NPs are beneficial for cell imaging, wastewater treatment and therapeutics.

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